DOCSLIB.ORG

UAS Autopilot

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
UAS Autopilot UAS Autopilot Phil Baldwin Purdue University – AAE 1/22/2018 Outline • Theory • Guidance • Navigation • Control • Hardware • Setup • Testing • Software • Choices • Use • Testing Northrop Grumman X-47B: Autonomous aerial refueling • Integration 2 Theory • Goal: Control full non-linear EOMs of your 6 DoF system (aircraft) • How : • Identify behavior of your aircraft: Parameter Identification • Provide controller for each dynamic mode that doesn’t behave how you want it to (Dutch roll, phugoid, etc.) • Provide controller for guidance/navigation • Navigation: Where you are • Guidance: Where you’re going • Ground station software rolls all this into one package, with most of the work already done for you, though it is not necessarily all-encompassing 3 Theory – Parameter Identification • Goal: Find stability derivatives • Relates the movement of a control surface, CG position shift, velocity, etc. to the reaction that the aircraft will have • Difficult to calculate by hand • Predicted values – will need to coordinate values from several different sources • CFD • CAD • AVL • Measured values • Flight tests: Accelerometers and airspeed are most common data • Wind tunnel: May be able to provide some data 4 Theory – Controllers • Goal: Provide controller for each dynamic mode that doesn’t behave how you want it to (Dutch roll, phugoid, etc.) • Generally use linearized EOMs and successive loop closure to create controllers for each system • Define system inputs and outputs (e.g., elevator signal input, AoA output) • PID Control in Ground Station software • Can implement additional filters 5 Theory – Navigation • Goal: Know where you are • Sources • GNSS (GPS, GLONASS, Galileo, BeiDou) • RTK for more precise positioning – requires extra hardware • Inertial (Based on accelerometers and/or gyros) • Magnetic Compass (Magnetometer) • Barometer • Sensor fusion – Uses all of the above, with Kalman filtering, to provide a better solution to the problem • Not trivial • Built in to ground control software/firmware 6 Theory – Guidance • Goal: Get where you want to go • Driven by cross-track error: How far to the left or right (or below/above) are you of your desired track? • Generally a controller gain set to define how “aggressively” you want to get to your desired track • May be limited by bank angle limit, airspeed, or other factors • How close is close enough? • Is it the same in all phases of your flight plan? 7 Hardware None of us are equipped to deal with a severed finger (duct tape can only go so far). Please take steps to ensure that you stay safe when conducting bench, testbed, or production aircraft tests. Ideally, perform all tests without a propeller attached. Only attach a propeller once you are read to go fly. 8 Hardware • A hardware solution that will allow for easy integration and that will allow you to connect servos, ESCs, radio receiver, etc., is desirable • Pixhawk is the most common by far • Pixhawk 2 is newer, with different connector types (and very nice) • Pixhawk Mini the same, but smaller • Some projects based on Raspberry Pi • Additional “nice to have” (might be required, depending on mission design) components • External GPS • Pitot-static system 9 Hardware • Pixhawk • Onboard IMU (accelerometers, gyros, barometer, magnetometer) • Lots of extra connectivity options • I2C • UART • CAN • ADC • … • Telemetry/control radio is nice to have • Each team already working? 10 Hardware – Setup • Not going to describe each individual step here • Lots of tutorials available online • Not enough time • Install Pixhawk unit as near the CG as possible (arrow facing forward for all software defaults) • Forward-aft adjustment easiest • Vertical also important, but less variation • Foam or rubber to dampen vibrations • Attach all electrical connections • Verify servo connections not reversed anywhere (very common) • Don’t stretch wires taut • Try to avoid a rat’s nest 11 Hardware – Servo Wires White/Yellow/Orange: PWM Signal Red: +VDC Black/Brown: -VDC RIGHT WRONG • Easiest way to avoid issues is to standardize all servos and wires, but that takes some additional planning • Custom-length servo wires take longer to integrate but probably will save some weight and space 12 Hardware – Testing • Bench testing highly recommended before installation in airframe • Chances are your final aircraft will not be ready for integration before you get all of your autopilot components together • Pre-assemble/test as much of the system as possible • Include as much of the actual system you will use • Servo extensions • Cameras • Transmitters • A couple of pieces of wood or foam will work – doesn’t need to be complex • Allow access to Pixhawk and other components to check connections or current conditions • Much harder to dig around inside of a fuselage and trace wires 13 Hardware – Testing • Testbed aircraft • Use to test/practice… • Assembly/start-up steps • Ground station practice • Flight modes • Sensors (airspeed, cameras) • Can use to create or refine… • Stability models and tuning • Methods for data collection • Use a known stable design • Mitigate risk of using the autopilot the first time in your only aircraft 14 Software – Choices • Lots of options, especially depending on platform; can use a tablet or desktop (laptop) based system • Mission Planner* • APM Planner 2 • QGroundControl • UgCS • No “right” answer; download one or all of them, they are all free • Spend some time using each one • Steep learning curve for new users • Best way to learn it is to use it *I’ll be using links to this software. QGC has analogs to most of the links I provide. 15 Software – Uses • Control • Mission Planning • Waypoints • Vertical (profile) planning • Point of interest (loiter, circle) • Component integration • Cameras • Sensors • Joystick (if you want) • Telemetry • Real-time info on location, speed, ETA, etc. • Diagnostic/status info 16 Software – Uses • Telemetry channels • To prevent interference with other teams • Steps 1. Plug both radios in (one to GCS via USB, other to telem port) 2. Connect 3. Initial Setup → Optional Hardware → SiK Radio 4. “Load Settings” 5. Change Net ID 6. Copy Req’d to Remote • Alternate: Connect each to GCS via USB independently, *Older version of Mission Planner shown then change Net ID 17 Software – Uses • Mission Planner Setup • Units (make sure they match what you are designing in) • Telemetry rates • Higher rate = finer data, may lose some data over telemetry (depends on aircraft configuration, geography, etc.) • Log Path • To find telemetry logs after flight • Advanced mode • Enables full parameter list and tree 18 Software – Uses • Simulation • Standard “plane” uses default gain values to guess how your airplane will fly – you need to update the defaults to be able to simulate your airplane without it connected • With your real plane connected (via USB or telemetry), see how servos react, cameras point • Will not be perfect; fidelity is fairly low • Use to test out new mission profiles • Use to teach additional team members to operate your plane 19 Software – Uses • Simulation • Click “Simulation” • Select Model • Click “Plane” • Will load SITL items • Initializes a simulated plane • Can interact just as if it was a real plane • Load waypoints • In-situ mission (takeoff, loiter, point camera, etc.) • Change parameters on-the-fly • Disconnect “TCP” to stop 20 Software – Uses • A word on waypoint definition • Defined as a 3-Dimensional point • Latitude, Longitude, Altitude • Built-in Lat-Long “tolerance” • Radius (NOT diameter) • As soon as the aircraft is within radius, the next waypoint is sequenced • Be careful with altitude definition • Absolute = MSL • Terrain = AGL • Relative = Compared to Home point 21 Software – Testing • Same pretense as hardware testing: Know what you’re getting into and practice it • Set up Pixhawk to be able to talk to your ground station • Test out different modes in testbed • Use ground station and RC transmitter to change modes • Understand what the software is doing; don’t just assume it will do what you want it to • Know how to set the failsafe and what to expect if it takes effect • Always be ready to take control back from the autopilot • Know where the “Manual” or “Override” switch is and how to use it 22 Integration • Probably the hardest part of all of this (in the build process), but the least material to talk about • All of the airplanes are different • All of the missions are different • Must relate specific performance of each given system to your KPIs and decide what needs done first • This will take you longer than you think, unless you have specifically designed how to integrate each individual component (down to servo wires) into your airframe • Generally there is ample tape used in this process 23 Integration • Make sure you can access Pixhawk to plug components in • Install components individually • Servos • ESC • Camera(s) • Pitot-static tube • Lidar/other rangefinder • GPS Antenna • Pixhawk unit (and associated accessories) • Radio transceivers 24 Integration • Make sure everything works individually before plugging in to Pixhawk • Common to think the Pixhawk is malfunctioning, but there is actually a servo extension installed upside down in line • Use a servo tester • Ensure prop rotation direction is correct (also a common “Oops” moment, but sometimes fixable with ESC programming) • Plug in all components to Pixhawk • Should already have wireless ground control connection made, right? • Take care with the tiny connectors (pins are easy to bend, plastic is brittle)
Load more

Recommended publications
  • ALT / VS Selector/Alerter
    ALT / VS Selector / Alerter PN 01279-( ) Pilot’s Operating Handbook ENT ALT SEL ALR DH VS BARO S–TEC * Asterisk indicates pages changed, added, or deleted by List of Effective Pages current revision. Retain this record in front of handbook. Upon receipt of a Record of Revisions revision, insert changes and complete table below. Revision Number Revision Date Insertion Date/Initials 1st Ed. Oct 26, 00 2nd Ed. Jan 15, 08 3rd Ed. Jun 24, 16 3rd Ed. Jun 24, 16 i S–TEC Page Intentionally Blank ii 3rd Ed. Jun 24, 16 S–TEC Table of Contents Sec. Pg. 1 Overview...........................................................................................................1–1 1.1 Document Organization....................................................................1–3 1.2 Purpose..............................................................................................1–3 1.3 General Control Theory....................................................................1–3 1.4 Block Diagram....................................................................................1–4 2 Pre-Flight Procedures...................................................................................2–1 2.1 Pre-Flight Test....................................................................................2–3 3 In-Flight Procedures......................................................................................3–1 3.1 Selector / Alerter Operation..............................................................3–3 3.1.1 Data Entry.............................................................................3–3
    [Show full text]
  • How Doc Draper Became the Father of Inertial Guidance
    (Preprint) AAS 18-121 HOW DOC DRAPER BECAME THE FATHER OF INERTIAL GUIDANCE Philip D. Hattis* With Missouri roots, a Stanford Psychology degree, and a variety of MIT de- grees, Charles Stark “Doc” Draper formulated the basis for reliable and accurate gyro-based sensing technology that enabled the first and many subsequent iner- tial navigation systems. Working with colleagues and students, he created an Instrumentation Laboratory that developed bombsights that changed the balance of World War II in the Pacific. His engineering teams then went on to develop ever smaller and more accurate inertial navigation for aircraft, submarines, stra- tegic missiles, and spaceflight. The resulting inertial navigation systems enable national security, took humans to the Moon, and continue to find new applica- tions. This paper discusses the history of Draper’s path to becoming known as the “Father of Inertial Guidance.” FROM DRAPER’S MISSOURI ROOTS TO MIT ENGINEERING Charles Stark Draper was born in 1901 in Windsor Missouri. His father was a dentist and his mother (nee Stark) was a school teacher. The Stark family developed the Stark apple that was popular in the Midwest and raised the family to prominence1 including a cousin, Lloyd Stark, who became governor of Missouri in 1937. Draper was known to his family and friends as Stark (Figure 1), and later in life was known by colleagues as Doc. During his teenage years, Draper enjoyed tinkering with automobiles. He also worked as an electric linesman (Figure 2), and at age 15 began a liberal arts education at the University of Mis- souri in Rolla.
    [Show full text]
  • Installation Manual, Document Number 200-800-0002 Or Later Approved Revision, Is Followed
    9800 Martel Road Lenoir City, TN 37772 PPAAVV8800 High-fidelity Audio-Video In-Flight Entertainment System With DVD/MP3/CD Player and Radio Receiver STC-PMA Document P/N 200-800-0101 Revision 6 September 2005 Installation and Operation Manual Warranty is not valid unless this product is installed by an Authorized PS Engineering dealer or if a PS Engineering harness is purchased. PS Engineering, Inc. 2005 © Copyright Notice Any reproduction or retransmittal of this publication, or any portion thereof, without the expressed written permission of PS Engi- neering, Inc. is strictly prohibited. For further information contact the Publications Manager at PS Engineering, Inc., 9800 Martel Road, Lenoir City, TN 37772. Phone (865) 988-9800. Table of Contents SECTION I GENERAL INFORMATION........................................................................ 1-1 1.1 INTRODUCTION........................................................................................................... 1-1 1.2 SCOPE ............................................................................................................................. 1-1 1.3 EQUIPMENT DESCRIPTION ..................................................................................... 1-1 1.4 APPROVAL BASIS (PENDING) ..................................................................................... 1-1 1.5 SPECIFICATIONS......................................................................................................... 1-2 1.6 EQUIPMENT SUPPLIED ............................................................................................
    [Show full text]
  • Using an Autothrottle to Compare Techniques for Saving Fuel on A
    Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2010 Using an autothrottle ot compare techniques for saving fuel on a regional jet aircraft Rebecca Marie Johnson Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Electrical and Computer Engineering Commons Recommended Citation Johnson, Rebecca Marie, "Using an autothrottle ot compare techniques for saving fuel on a regional jet aircraft" (2010). Graduate Theses and Dissertations. 11358. https://lib.dr.iastate.edu/etd/11358 This Thesis is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Using an autothrottle to compare techniques for saving fuel on A regional jet aircraft by Rebecca Marie Johnson A thesis submitted to the graduate faculty in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Major: Electrical Engineering Program of Study Committee: Umesh Vaidya, Major Professor Qingze Zou Baskar Ganapathayasubramanian Iowa State University Ames, Iowa 2010 Copyright c Rebecca Marie Johnson, 2010. All rights reserved. ii DEDICATION I gratefully acknowledge everyone who contributed to the successful completion of this research. Bill Piche, my supervisor at Rockwell Collins, was supportive from day one, as were many of my colleagues. I also appreciate the efforts of my thesis committee, Drs. Umesh Vaidya, Qingze Zou, and Baskar Ganapathayasubramanian. I would also like to thank Dr.
    [Show full text]
  • P:\Dokumentation\Manual-O\DA 62\7.01.25-E
    DA 62 AFM Ice Protection System Supplement S03 FIKI SUPPLEMENT S03 TO THE AIRPLANE FLIGHT MANUAL DA 62 ICE PROTECTION SYSTEM FOR FLIGHT INTO KNOWN ICING Doc. No. : 7.01.25-E Date of Issue of the Supplement : 01-Apr-2016 Design Change Advisory : OÄM 62-003 This Supplement to the Airplane Flight Manual is EASA approved under Approval Number EASA 10058874. This AFM - Supplement is approved in accordance with 14 CFR Section 21.29 for U.S. registered aircraft and is approved by the Federal Aviation Administration. DIAMOND AIRCRAFT INDUSTRIES GMBH N.A. OTTO-STR. 5 A-2700 WIENER NEUSTADT AUSTRIA Page 9-S03-1 Ice Protection System DA 62 AFM FIKI Supplement S03 Intentionally left blank. › Page 9-S03-2 05-May-2017 Rev. 2 Doc. # 7.01.25-E DA 62 AFM Ice Protection System Supplement S03 FIKI 0.1 RECORD OF REVISIONS Rev. Chap- Date of Approval Date of Date Signature Reason Page(s) No. ter Revision Note Approval Inserted Rev. 1 to AFM Supplement S03 to AFM 9-S03-1, Doc. No. FAA 7.01.25-E is 1 0 9-S03-3, 10 Oct 2016 14 Oct 2016 Approval approved by 9-S03-4 EASA with Approval No. EASA 10058874 › Rev. 2 to AFM › Supplement › S03 to AFM › Doc. No. › TR-MÄM › All, except 7.01.25-E is › 2 62-254, 05 May 2017 › All approved 13 Nov 2017 › Corrections Cover Page › under the › authority of › DOA › No.21J.052 › Doc. # 7.01.25-E Rev. 2 05-May-2017 Page 9-S03-3 Ice Protection System DA 62 AFM FIKI Supplement S03 0.3 LIST OF EFFECTIVE PAGES Chapter Page Date 9-S03-1 10-Oct-2016 › 9-S03-2 05-May-2017 › 9-S03-3 05-May-2017 › 9-S03-4 05-May-2017 0 › 9-S03-5 05-May-2017 › 9-S03-6 05-May-2017 › 9-S03-7 05-May-2017 › 9-S03-8 05-May-2017 › 9-S03-9 05-May-2017 › 9-S03-10 05-May-2017 1 › 9-S03-11 05-May-2017 › 9-S03-12 05-May-2017 › appr.
    [Show full text]
  • Ac 120-67 3/18/97
    Advisory u.s. Department ofTransportation Federal Aviation Circular Ad.nnlstratlon Subject: CRITERIA FOR OPERATIONAL Date: 3/18/97 AC No: 120-67 APPROVAL OF AUTO FLIGHT Initiated By: AFS-400 Change: GUIDANCE SYSTEMS 1. PURPOSE. This advisory circular (AC) states an acceptable means, but not the only means, for obtaining operational approval of the initial engagement or use of an Auto Flight Guidance System (AFGS) under Title 14 of the Code of Federal Regulations (14 CFR) part 121, section 121.579(d); part 125, section 125.329(e); and part 135, section 135.93(e) for the takeoff and initial climb phase of flight. 2. APPLICABILITY. The criteria contained in this AC are applicable to operators using commercial turbojet and turboprop aircraft holding Federal Aviation Administration (FAA) operating authority issued under SPAR 38-2 and 14 CFR parts 119, 121, 125, and 135. The FAA may approve the AFGS operation for the operators under these parts, where necessary, by amending the applicant's operations specifications (OPSPECS). 3. BACKGROUND. The purpose of this AC is to take advantage of technological improvements in the operational capabilities of autopilot systems, particularly at lower altitudes. This AC complements a rule change that would allow the use of an autopilot, certificated and operationally approved by the FAA, at altitudes less than 500 feet above ground level in the vertical plane and in accordance with sections 121.189 and 135.367, in the lateral plane. 4. DEFINITIONS. a. Airplane Flight Manual (AFM). A document (under 14 CFR part 25, section 25.1581) which is used to obtain an FAA type certificate.
    [Show full text]
  • Digital Fly-By-Wire
    TF-2001-02 DFRC Digital Fly-By-Wire "The All-Electric Airplane" Skies around the world are being filled with a new generation of military and commercial aircraft, and the majority of them are beneficiaries of one of the most significant and successful research programs conducted by NASA's Dryden Flight Research Center -- the Digital Fly-By-Wire flight control system. The Dryden DFBW program has changed the way commercial and military aircraft are designed and flown. Aircraft with fly-by- wire systems are safer, more reliable, easier to fly, more NASA F-8 modified to test a digital fly-by-wire flight control system. maneuverable and fuel NASA Photo ECN 3276 efficient, and maintenance costs are reduced. Flight control systems link pilots in their cockpits with moveable control surfaces out on the wings and tails. These control surfaces give aircraft directional movement to climb, bank, turn, and descend. Since the beginning of controlled flight in the early 1900s, wires, cables, bellcranks, and pushrods were the traditional means of connecting the control surfaces to the control sticks and rudder pedals in the cockpits. As aircraft grew in weight and size, hydraulic mechanisms were added as boosters because more power was needed to move the controls. The Digital Fly-By-Wire (DFBW) program, flown from 1972 to 1985, proved that an electronic flight control system, teamed with a digital computer, could successfully replace mechanical control systems. 1 Electric wires are the linkage between the cockpit automatically compensates -- as many as 40 and control surfaces on a DFBW aircraft. Command commands a second -- to keep the aircraft in a stable signals from the cockpit are processed by the digital environment.
    [Show full text]
  • A Historical Overview of Flight Flutter Testing
    tV - "J -_ r -.,..3 NASA Technical Memorandum 4720 /_ _<--> A Historical Overview of Flight Flutter Testing Michael W. Kehoe October 1995 (NASA-TN-4?20) A HISTORICAL N96-14084 OVEnVIEW OF FLIGHT FLUTTER TESTING (NASA. Oryden Flight Research Center) ZO Unclas H1/05 0075823 NASA Technical Memorandum 4720 A Historical Overview of Flight Flutter Testing Michael W. Kehoe Dryden Flight Research Center Edwards, California National Aeronautics and Space Administration Office of Management Scientific and Technical Information Program 1995 SUMMARY m i This paper reviews the test techniques developed over the last several decades for flight flutter testing of aircraft. Structural excitation systems, instrumentation systems, Maximum digital data preprocessing, and parameter identification response algorithms (for frequency and damping estimates from the amplltude response data) are described. Practical experiences and example test programs illustrate the combined, integrated effectiveness of the various approaches used. Finally, com- i ments regarding the direction of future developments and Ii needs are presented. 0 Vflutte r Airspeed _c_7_ INTRODUCTION Figure 1. Von Schlippe's flight flutter test method. Aeroelastic flutter involves the unfavorable interaction of aerodynamic, elastic, and inertia forces on structures to and response data analysis. Flutter testing, however, is still produce an unstable oscillation that often results in struc- a hazardous test for several reasons. First, one still must fly tural failure. High-speed aircraft are most susceptible to close to actual flutter speeds before imminent instabilities flutter although flutter has occurred at speeds of 55 mph on can be detected. Second, subcritical damping trends can- home-built aircraft. In fact, no speed regime is truly not be accurately extrapolated to predict stability at higher immune from flutter.
    [Show full text]
  • Wing Tip.Qxd
    WINGTIP COUPLING AT 15,000 FEET Dangerous Experiments by C.E. “Bud” Anderson ingtip coupling evolved from an invention by Dr. Richard Vogt, a German scientist who emigrated to W the U.S. after WW II. The basic con- cept involved increasing an aircraft’s range by attaching two “free-floating,” fuel-carrying aerodynamic panels to the wingtips. This could be accomplished without undue struc- tural weight penalties as long as the panels were free to articulate and support themselves with their own aerodynamic lift. The panels would increase the basic wing configuration’s aspect ratio and would therefore significantly reduce induced drag; the “free” extra fuel car- ried by this more efficient wing would consid- erably increase an aircraft’s range. Soon, other logical uses of this unusual concept became apparent: for example, two escort fighters might be carried along “free” on a large bomber without sacrificing its range. To be feasible, the wingtip extensions, But there was also the problem of how such fuel-carrying extensions could be handled on the ground. How would they be supported without airflow to or panels, whatever they were, would have to hold them up?—perhaps by the use of a retractable outrigger landing gear, but what about runway width requirements? And—the big question—what about be kept properly aligned, preferably by a sim- the stability and control problems that might be induced by such a configura- ple and automatic flight-control system. tion; would the extensions be easy to control? Many questions are also immedi- 64 FLIGHT JOURNAL The second wingtip-coupling experiment involved an ETB-29A and two EF-84Bs (photo courtesy of Peter M.
    [Show full text]
  • Radio Altimeter Industry Coalition Coalition Overview David Silver, Aerospace Industries Association
    Radio Altimeter Industry Coalition Coalition Overview David Silver, Aerospace Industries Association 7/1/2021 2 Background • The aviation industry, working through a multi-stakeholder group formed after open, public invitation by RTCA, conducted a study to determine interference threshold to radio altimeters • The study found that 5G systems operating in the 3.7-3.98 GHz band will cause harmful interference altimeter systems operating in the 4.2- 4.4 GHz band – and in some cases far exceed interference thresholds • Harmful interference has the serious potential to impact public and aviation safety, create delays in aircraft operations, and prevent operations responding to emergency situations 7/1/2021 3 Goals and Way Forward • To ensure the safety of the public and aviation community, government, manufacturers, and operators must work together to: • Further refine the full scope of the interference threat • Determine operational environments affected • Identify technical solutions that will resolve interference issues • Develop future standards • Government needs to bring the telecom and aviation industries to the table to refine understanding of the extent of the problem and collaboratively develop mitigations to address the changing spectrum environment near-, mid-, and long- term. 7/1/2021 4 Coalition Tech-Ops Presentation John Shea, Helicopter Association International Sai Kalyanaraman, Ph.D., Collins Aerospace 7/1/2021 5 What is a Radar Altimeter? • Radar altimeters are the only device on the aircraft that can directly measure the distance between the aircraft and the ground and only operate in 4200-4400 MHz • Operate when the aircraft is on the surface to over 2500’ above ground Radar Altimeter Antennas Radar Altimeter Antennas Photo credit: Honeywell Photo credit: ALPA 7/1/2021 6 How Does a Radar Altimeter Work? 1.
    [Show full text]
  • Performance and Flexibility
    LRA-2100 low range altimeter LRA-2100 LOW RANGE ALTIMETER PERFORMANCE AND FLEXIBILITY The next-generation LRA-2100 low range The all-digital design of the LRA-2100 altimeter from Collins Aerospace delivers improves the overall accuracy of the advances made possible through our altitude solution by being able to detect extensive, proven experience with software- and filter errors associated with antenna defined radio technology. or cable leakage. Additionally, the LRA- KEY FEATURES AND BENEFITS 2100 can isolate the leakage and provide The LRA-2100 is a radio altimeter that information to the maintenance computer • Lower probability of autopilot provides precise, digital height measurements to instigate the proper maintenance disconnects above terrain during aircraft approach, action and improve overall availability – Homogeneity performance landing and climb-out phases of flight. This of the system. between altimeters information is provided to the automatic – Accuracy, especially over flight control system, instrument system The digital design also eliminates ambiguity challenging terrain and objects and terrain awareness and warning system. in the altitude solution by being able to on approach more accurately determine the source of The LRA-2100 offers a wide range of multiple returns. This ability allows the • Greater safety and availability advantages through use of the industry’s LRA-2100 to identify each target and report – Antenna leakage detection most advanced technologies. These the best result. It allows the LRA-2100 and cancellation advantages include: to reject erroneous altitude returns from • Improved aircraft maintainability under-flying aircraft that persist for more • Complete digital design – Detects and isolates bad antenna than 2.5 seconds and from other ground or RF coaxial cable installation • Latest component technology and structures such as landing lights, bridges issues advanced manufacturing processes and overpasses.
    [Show full text]
  • Approaches to Assure Safety in Fly-By-Wire Systems: Airbus Vs
    APPROACHES TO ASSURE SAFETY IN FLY-BY-WIRE SYSTEMS: AIRBUS VS. BOEING Andrew J. Kornecki, Kimberley Hall Embry Riddle Aeronautical University Daytona Beach, FL USA <[email protected]> ABSTRACT The aircraft manufacturers examined for this paper are Fly-by-wire (FBW) is a flight control system using Airbus Industries and The Boeing Company. The entire computers and relatively light electrical wires to replace Airbus production line starting with A320 and the Boeing conventional direct mechanical linkage between a pilot’s 777 utilize fly-by-wire technology. cockpit controls and moving surfaces. FBW systems have been in use in guided missiles and subsequently in The first section of the paper presents an overview of military aircraft. The delay in commercial aircraft FBW technology highlighting the issues associated with implementation was due to the time required to develop its use. The second and third sections address the appropriate failure survival technologies providing an approaches used by Airbus and Boeing, respectively. In adequate level of safety, reliability and availability. each section, the nature of the FBW implementation and Software generation contributes significantly to the total the human-computer interaction issues that result from engineering development cost of the high integrity digital these implementations for specific aircraft are addressed. FBW systems. Issues related to software and redundancy Specific examples of software-related safety features, techniques are discussed. The leading commercial aircraft such as flight envelope limits, are discussed. The final manufacturers, such as Airbus and Boeing, exploit FBW section compares the approaches and general conclusions controls in their civil airliners. The paper presents their regarding the use of FBW technology.
    [Show full text]